Multi LNB Set up on a Sky Dish

[jeallen01]

How straight does the pole have to be? I have a trampoline pole, but it has a slight taper

Might be OK as a "short" pole, but not for what you seem to need - maybe OK for a Zone 2 dish, but probably not rigid enough for a motor/dish combo.

 

[ozumo]

(and not forgetting the unused 20yr old Raven 90, currently "parked" on a vegi bed under the Gibby - anyone want that??)

Is that one of those wider-than-tall oval dishes?

 

[Channel Hopper]

Unless you are motorising, the pole can be at almost any angle.

 

[Offtensive]

Is there a way to check my line on sight without using an app? As I don’t think they’re giving me an accurate answer.

I have the following method but I’m not sure if it is spot on.

I was thinking, say if the satellite I want is at 21.8 degrees elevation based on my location and the azimuth is 130 degrees. Tan 21.8 is 0.4.

So I face 130 degrees based on a compass. And if there is an obstruction in the way, for every 1m I am away from that obstruction I clear 40cm.

So if I’m say 5m away and there’s an obstruction 4.5m high, I would have to have my dish at a height of at least 2.5m?

 

[jeallen01]

Have you tried using dishpointer.com as that's fairly accurate?

 

[jeallen01]

Is that one of those wider-than-tall oval dishes?

Yes - it's a Gemini 90 (no LNB holder/clamp on the end of it ATM, but at least most of that should be in the garage)

I bought it around 1998'ish and fitted it with 4 or 5 LNBs covering (IIRC) 28E to 1W - although at least one of those was way, way away from the feedarm LNB holder on an "extension piece"!

Tried to use it down the garden several times in recent years, but the large dish-mount and the long feedarm mean that it's a heavy bugger and that the LNB holder almost sticks out over the path and so gets knocked pretty often - also, I think I've lost the "knack" of aligning LNBs on that dish - and so I gave up on that idea!

 

[ozumo]

So if I’m say 5m away and there’s an obstruction 4.5m high, I would have to have my dish at a height of at least 2.5m?

45 divided by elevation gives you the ratio of how far back the dish needs to be. So 45 divided by 21.8° = around 2.064M back for every 1M of obstruction. For azimuth work from true north, not magnetic

 

[ozumo]

Yes - it's a Gemini 90 (no LNB holder/clamp on the end of it ATM, but at least most of that should be in the garage)

I bought it around 1998'ish and fitted it with 4 or 5 LNBs covering (IIRC) 28E to 1W - although at least one of those was way, way away from the feedarm LNB holder on an "extension piece"!

Tried to use it down the garden several times in recent years, but the large dish-mount and the long feedarm mean that it's a heavy bugger and that the LNB holder almost sticks out over the path and so gets knocked pretty often - also, I think I've lost the "knack" of aligning LNBs on that dish - and so I gave up on that idea!

I always wanted one of those as they looked just like a larger version of a Zone 2

 

[a33]

Have you tried using dishpointer.com as that's fairly accurate?

@Offtensive
Also the sun is pretty accurate for finding the correct azimuth.
I use Satellite Look Angle Calculator
to find the time at a certain date, that the sun has exactly the same azimuth as the satellite.

After that, only checking the elevation is needed; as you described (your 2.5 meter would be the BOTTOM of the dish).

Greetz,
A33

 

[jeallen01]

I always wanted one of those as they looked just like a larger version of a Zone 2

A damned sight larger & heavier

 

[ozumo]

A damned sight larger & heavier

Much prefer heavy & sturdy compared to light & flimsy

 

[Channel Hopper]

I always wanted one of those as they looked just like a larger version of a Zone 2

You've not seen the 1.4m version then.

 

[ozumo]

You've not seen the 1.4m version then.

No, did not know such a dish existed.

 

[jeallen01]

You've not seen the 1.4m version then.

No, did not know such a dish existed.

"Latest" info I have was the largest version was 1.2m - so where/when was there a 1.4m version??

PS: if that actually existed, then it must have been "F***ing heavy"!

 

[Channel Hopper]

"Latest" info I have was the largest version was 1.2m - so where/when was there a 1.4m version??

PS: if that actually existed, then it must have been "F***ing heavy"!

It was, and may have been the last in house Concentric design before getting swallowed.

 

[Offtensive]

Can I put a zone 1 dish on a 50mm pole, or possibly even a zone 2?

I've heard quite a few conflicting reports from other forums and websites.

 

[ozumo]

Both are possible. With a zone 2 it's probably easiest to use a pole-to-pole clamp and attach a smaller pole to the 50mm one. Make sure the clamp allows for a gap between the poles so there is room to align the dish.

A zone 1 has prevision for pole mounting on its horizontal bar. May need some hole enlarging to allow a 50mm U-bolt to fit.

 

[Offtensive]

Is this the pole to pole clamp?

Shelly Mast Clamp Bracket | 1” – 2 Inch Pole Bracket | 8 Nut Aerial Bolt Universal Steel Extension | TV Wall Mounting Kit | Loops: Amazon.co.uk: Electronics & Photo

Free delivery and returns on eligible orders. Buy Shelly Mast Clamp Bracket | 1” – 2 Inch Pole Bracket | 8 Nut Aerial Bolt Universal Steel Extension | TV Wall Mounting Kit | Loops at Amazon UK.

www.amazon.co.uk

Thanks

 

[ozumo]

Is this the pole to pole clamp?

Shelly Mast Clamp Bracket | 1” – 2 Inch Pole Bracket | 8 Nut Aerial Bolt Universal Steel Extension | TV Wall Mounting Kit | Loops: Amazon.co.uk: Electronics & Photo

Free delivery and returns on eligible orders. Buy Shelly Mast Clamp Bracket | 1” – 2 Inch Pole Bracket | 8 Nut Aerial Bolt Universal Steel Extension | TV Wall Mounting Kit | Loops at Amazon UK.

www.amazon.co.uk

Thanks

Yes but the poles would be very close to each other. I would use something like this where you could use nuts to space the poles apart.

Eseno Satellite Wall Clamp Set. 2pce 60 x 130mm: Amazon.co.uk: Electronics & Photo

Free delivery and returns on eligible orders. Buy Eseno Satellite Wall Clamp Set. 2pce 60 x 130mm at Amazon UK.

www.amazon.co.uk

 

[Offtensive]

@Offtensive
Also the sun is pretty accurate for finding the correct azimuth.
I use Satellite Look Angle Calculator
to find the time at a certain date, that the sun has exactly the same azimuth as the satellite.

After that, only checking the elevation is needed; as you described (your 2.5 meter would be the BOTTOM of the dish).

Greetz,
A33

I gave this a go today. I zoomed in on my location in the map, the coordinates it gives are constant with the ones that I get from google maps if I do it via their app/site too.

Then I picked the satellite and entered the date.

My understanding is that now the satellite will be below the sun. So say if this website is giving me 40 degrees as the elevation for the sun, and the satellite is at 20 degrees elevation. I look in the same direction, but with half the elevation right?